Why isn't Google accepting other types of vector data, such as existing roads and addresses rather than just new roads and addresses, or other types of map content?

Our goal is to expand the coverage of our base map while continually improving its accuracy. The vector data types we accept represent the features we are now adding to the base map. If you have data for features that don't appear in our base map, or if you have other map content types you would like to add to Google's services, tell us about your organization and your data.